1. Field of the Invention
The present invention relates to improvement of a member having an internal cooling passage, and more particularly, to improvement of a member having an internal cooling passage with a wall surface which possesses cooling ribs.
2. Description of Related Art
In the related art, for improvement of heat transfer efficiency in an internal cooling passage of a member, a method of causing turbulence flow in air flow of a heat transfer surface or destroying a boundary layer is known. In addition, there is a method of providing a plurality of protrusions on a blade.
For example, in JP-A-05-10101 (U.S. Pat. No. 5,395,212; FIG. 3), a plurality of ribs is provided in the internal cooling passage of a member and arranged in a staggered manner with respect to flow of a medium in the cooling passage such that turbulent flow is caused in the medium on a heat transfer surface to obtain a large cooling heat transfer coefficient.
In addition, in JP-A-2000-282804 (FIG. 10), there is disclosed a cooling passage in which ribs arranged in a staggered manner are divided and ribs at the side of wall surfaces are arranged at an upstream side of a medium.